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Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.

Notre mission : apporter un enseignement gratuit et de qualité à tout le monde, partout. Plus de 6 000 vidéos et des dizaines de milliers d'exercices interactifs sont disponibles du niveau primaire au niveau universitaire.

See how action potentials in neurons are generated and conducted. Explore the role of voltage-gated ion channels and how they open when the membrane potential crosses a threshold value, as well as the influx of sodium ions and efflux of potassium ions during an action potential, and the refractory period that follows.

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Khan Academy offers Blooket, a tool that combines teaching with engaging gameplay to make learning fun and memorable for students.

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2024年8月8日 · Physics: Unraveling the universe’s mysteries. Our new high school physics course invites students to explore the fundamental principles that govern the universe, from forces and energy to electromagnetism. Learners will examine and be able to explain everyday observations, such as the motion of a ball, static electricity, and why the sky is blue.

If you're seeing this message, it means we're having trouble loading external resources on our website. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.